KR20030051765A - Etching of high aspect ratio features in a substrate - Google Patents

Abstract

The substrate processing chamber 110 includes a gas supply 56 for providing gas to the chamber, first and second electrodes 115 and 105 electrically biased to energize the gas, and an exhauster 110 for discharging the gas. Wherein the second electrode 115 is configured to be charged at a power density of at least about 10 watts / cm 2 and has a receiving surface 147 for receiving the substrate 10.

Description

Etching of high aspect ratio non-formers in a substrate {ECHING OF HIGH ASPECT RATIO FEATURES IN A SUBSTRATE}

Process gases or their plasmas are often used to process substrates in chambers during substrate manufacture. Typically, the material is formed on a substrate by chemical vapor deposition (CVD), physical vapor deposition (PVD), ion implantation, oxidation or reduction processes, or the like. Subsequently, a portion of the substrate material, which is usually formed in the shape of a layer but may have another shape, is processed by etching or the like to be shaped into a cavity, a channel, a hole, a trench, or the like. It may be formed into an etching body.

In particular, when the formation has a small opening size, it is difficult to etch the formation having a high aspect ratio in the substrate material. Typically, advances in technology to provide faster and more efficient circuits require miniaturization of the spacing, thus increasing the aspect ratio of formations such as trenches, holes or vias. The aspect ratio is the ratio of the depth to the opening size of the formation. The high aspect ratio former has a aspect ratio of at least about 20, and the aperture size of the former may be about 0.18 μm or less. However, it is difficult to etch the high aspect ratio formation or the small opening formation without controlling the sidewalls of the formation with uncontrollable isotropic etching. Isotropic etching means that the sidewalls of the etched formation are etched in the horizontal direction at an etching rate that exceeds the vertical etching rate of the formation, which can lead to formations having undesirable shapes.

In other words, it is preferable to anisotropically etch the formation having a high aspect ratio or a small opening size. It is also desirable to etch into a formation having controllable and consistent dimensions over the substrate. It is also desirable for the substrate to be etched to have production value.

The present invention relates to a chamber and a method for etching a substrate.

These and other features, aspects, and advantages of the invention can be further understood by the following description, appended claims, and accompanying drawings that illustrate embodiments of the invention.

1A and 1B are schematic side cross-sectional views of a substrate before and after etching of a high aspect ratio formation in the substrate.

2 is a schematic cross-sectional view of an apparatus according to the present invention showing a processing chamber having an electrode, a magnetic field generator, and a controller.

3 is a schematic diagram of the magnetic field generator of FIG. 2.

4 is a schematic representation of another embodiment of a processing chamber in accordance with the present invention showing the chamber lid and the fluid circulation liner.

5 is a partial cross-sectional plan view of a chamber lid in accordance with the present invention.

6 is an exploded side view taken along the line 6-6 of the chamber lid of FIG.

7 is a partial cross-sectional plan view of another version of a chamber lid according to the present invention.

8 is a partial cross-sectional plan view of a chamber liner according to the present invention.

9 is a partial side cross-sectional view along section line 9-9 of the chamber liner of FIG. 8.

10 is a schematic partial cross-sectional view of another embodiment of a processing chamber according to the present invention.

11 is a block diagram of a computer software program according to the present invention.

12 is a graph illustrating an increase in temperature of a second electrode as power is increased during an etching process.

FIG. 13A is a graph showing changes in width and critical dimensions of etched formation with increasing power applied to the electrode. FIG.

FIG. 13B is a graph showing changes in width and critical dimensions of etched formation with increasing power applied to an electrode. FIG.

FIG. 13C is a graph showing changes in etching rate and etching selectivity of an etching process with increasing power applied to the electrode. FIG.

14A is a graph showing changes in width and critical dimensions of etched formation as increasing magnetic field strength.

FIG. 14B is a graph showing changes in etch rate and aspect ratio of etched formations with increasing magnetic field strength. FIG.

14C is a graph showing changes in etch rate and etch selectivity of an etch process with increasing magnetic field strength.

The present invention satisfies this need. In one aspect, the invention includes a gas supply for providing a gas to a chamber, first and second electrodes electrically biased to energize the gas, and an ejector for exhausting the gas, wherein the second electrode comprises: And a receiving surface adapted to be charged to a power density of at least about 10 watts / cm 2 and in which the substrate is received.

Another aspect of the invention includes providing a substrate in a processing region, injecting gas into the processing region, energizing the gas by applying electrical energy at a power density of at least about 10 watts / cm 2 to an electrode below the substrate, And discharging the gas.

In another aspect of the invention, a substrate etch chamber includes a substrate support, a gas provider for providing gas to the chamber and an ejector for discharging the gas to the chamber, the first and second being electrically biased to energize the gas. An electrode, a magnetic field generator configured to provide a magnetic field of at least about 100 Gauss to the chamber, and a temperature control system configured to control the temperature of the substrate and the chamber surface, the second electrode being configured for a substrate having a diameter of about 200 mm. It is configured to be able to charge with more than about 3200 watts of power.

Another aspect of the present invention provides a method of providing a substrate in a processing region of a chamber, injecting gas into the processing region, coupling the gas to electrical energy of at least about 3200 watts for a substrate having a diameter of about 200 mm. Energizing the substrate, applying a magnetic field of at least about 100 Gauss to the chamber, controlling the substrate and surface temperature of the chamber, and evacuating the gas.

Another aspect of the invention includes a substrate comprising an etched formation having an aspect ratio of at least about 30 and an aperture size of less than about 0.14 Φm.

The present invention includes a substrate 12 positioned below which may be provided with silicon, a compound semiconductor, or a dielectric, as shown by way of example in FIG. 1A; And one or more materials 22, 24, 26, such as polysilicon, dielectric or conductive material, on the substrate 12. As shown in the example in FIG. 1B, the substrate 10 is etched to form high aspect ratio forming bodies 29 such as trenches, holes, or vias in the materials 22, 24. For example, the holes and vias may be etched in silicon, polysilicon, or dielectric material, and in another embodiment, the trench may be a conductive material, such as a metal or an intermetallic compound, such as aluminum, copper, and metal silicide, or silicon. It may be etched in a dielectric material such as dioxide, silicon nitride or a low k dielectric material. Materials such as photoresist material 28 can be used to protect one area of the substrate 10 that is not etched away.

The present invention is particularly useful for etching the formed body 29 in the substrate 10 when the formed body 29 has a high aspect ratio. For example, the substrate 10 comprising one or more materials on the substrate 12 is etched to form an etched formation 29 having an aspect ratio of about 30 or more, and even about 45 or more. In addition, the formation 29 may be etched with an opening size of less than about 0.17 μm, and may even be less than about 0.14 μm or less than 0.10 μm. Etching of formation 29 having a small opening size is particularly useful when the opening size is the critical dimension of the etched formation. In addition, the formed body 29 may be etched to a depth of about 8 μm or more. Protective sidewall deposits 30 that may be formed during the etching process protect the sidewalls of the formed body 29 from isotropic etching. The rate at which the formations are etched may be at least about 0.8 [phi] m / mim.

An example of a device 50 according to the invention suitable for processing a substrate 10 is shown in FIG. 2. Typically, the device 50 defines a chamber volume 110 and has one or more walls 52, such as a circular sidewall 106, a bottom wall 108, a lid assembly 102, and one or more liners ( a process chamber 100 comprising a liner 104. Typically, chamber volume 110 is separated into treatment region 112 and pumping region 114. In and out of the chamber 100 through a slit opening 139 having a slit valve door 70 that provides a continuous circular surface of the chamber 100 and is operated vertically through a pneumatic motor 72. A robot 53 (dashed line in FIG. 2) for transporting the substrate 10 may be used. Although the present invention has been described with reference to an exemplary apparatus 50, this description is directed to etching other substrates, depositing material on the substrate 10 by PVD or CVD, or injecting material onto the substrate 10. It should be understood that the device configuration can be applied.

Gas, such as process gas, is injected into the chamber 100 through a gas source 97, one or more gas lines 103 having a valve 101, and a gas supplier 56 including a gas distributor 111. The gas distributor 111 may include a gas distribution plate 113 having a gas outlet 98 to allow gas to enter and exit the gas distributor 111, which also serves as an electrode. . Controller 160 may be used to control the flow rate, gas pressure, and other process chamber functions of the process gas. The spent process gas and by-products may include one or more discharge pumps via a throttle valve 60 used to control the gas pressure in the chamber 100 to an appropriate level, typically from about 5 mTorr to about 10 mTorr. It may be discharged through an ejector 114 connected with 109.

In one aspect of the invention, the pumping rate affects the formation of processing residues formed on the sidewalls and chamber walls of the etched formation, which are found to affect the etch quality of the high aspect ratio of the substrate 10. It became. Increasing the pumping rate is believed to reduce the formation of excess treatment residue on the sidewalls of the etched formation by effectively removing excess residue forming species in the chamber volume. Deposition of the processing residue to an optimal thickness on the sidewalls of the cleanly etched formation allows the etching to proceed vertically to the substrate without excess anisotropic etching of the formation sidewalls. However, especially for high aspect ratio formations having a small opening size and very deep, excess residue formation can interfere or stop etching. That is, in one version, the ejector 114 includes one or more pumps with sufficiently fast pumping speeds, thereby reducing further deposition of treatment residues on the substrate 10 and other surfaces of the chamber 100. For example, the discharger 114 may include a pump 109 capable of withdrawing exhaust gas at a rate of about 1600 L / s or more for a chamber volume of about 25 L from the chamber 100. For example, in one version, the pump 109 has a total pumping capacity and pumping speed of about 1600-1800 L / s for a chamber volume of about 25L.

An energizing gas, such as a plasma, in which electromagnetic energy such as RF or microwave energy is coupled to the gas, may be generated by the gas energizer 141. For example, the gas energizer 141 may include first and second electrodes 115, 105 that are electrically biased with each other to energize the gas in the chamber 100. The first electrode 115 may be a ceiling or sidewall of the chamber 100. The second electrode 105 is below the substrate 10 of the substrate support 124. Usually, the second electrode 105 is made of a conductive material such as aluminum, copper, gold, molybdenum, tantalum, titanium, tungsten, and metals such as alloys thereof. Molybdenum has good thermal conductivity and good resistance to corrosion in non-oxidizing atmospheres. Usually, the second electrode 105 is flattened and shaped according to the shape and size in the substrate 10, and its size is adjusted. For example, the second electrode 105 may be a conductive wire (not shown) mesh extending below the entire substrate 10. The second electrode 105 is covered with a dielectric 55 through which electromagnetic energy such as RF energy can penetrate, so that the energy applied to the electrode 105 and the gas in the chamber 100 are combined to form a plasma of the gas. Maintain and energize At least a portion of the dielectric 55 covers the electrode 105, and the other portion partially surrounds or totally encloses the electrode 105.

The first and second electrodes 115, 105 are provided with an electrode voltage via an impedance matching circuit 151 that matches the load impedance of the second electrode 105 in the selected frequency range with the impedance of the voltage supply 150 approximately equally. Electrically biased by the RF voltage provided by the feeder 150. The frequency of the RF voltage applied to the electrodes 115 and 105 may be from about 50 KHz to about 60 MHz. The voltage supply 150 may also be used to provide a DC chucking voltage to the electrode 105 to form an electrostatic charge on the electrode that secures the substrate 10. Typically, the DC voltage may be about 10 to about 2000 volts. In addition, the voltage supply 150 can be controlled by a controller 160 that can control the operation of the electrode 105. The gas energizer of an embodiment may be housed in other chamber versions apparent to those skilled in the art, and the gas energizer 141 has one or more coils in which RF energy is inductively coupled to the chamber by a microwave generator or through a microwave guide (not shown). Other versions, such as inductive antennas (not shown), may be included. In addition, the second electrode 105 may be configured to be electrically charged to electrostatically fix the substrate by a conventional DC voltage.

In another aspect of the present invention, the second electrode 105 and the covering dielectric 55 are charged such that the power density is high, which is the power applied by the second electrode 105 to the electrode 105 per unit area of the substrate 14. It is configured to provide good etching of the aspect ratio former of the substrate 14. The electrically biased second electrode 105 generates at least some electric field vector component that is substantially perpendicular to the plane of the substrate 10. Charged plasma ions of the energizing gas are accelerated by this vertically-oriented field component and strongly penetrate the substrate 10. As the magnitude of the power density of the second electrode 105 increases, the kinetic energy identified rises and is transferred directly to the charged plasma ions. As the kinetic energy increases, the plasma ions can more effectively etch the high aspect ratio former 29 and can better control the dimensions of the former 29. In one version, the second electrode 105 and the covering dielectric 55 are configured to sustain a power density of at least about 10 watts / cm 2. For a substrate 10 having a diameter of about 20 cm (200 mm), the appropriate power level applied to the second electrode 105 is at least about 3200 watts; For substrates having a diameter of about 30 cm (300 mm), suitable power levels are at least about 7000 watts.

The dielectric 55 covering the second electrode 105 is configured so that its composition and thickness are adjusted to withstand such high power levels without excess current leakage to the surrounding plasma or other chamber components. For example, in one version, dielectric 55 has a room temperature of about 1 × 10 ⁹ ohms-cm to about 1 × 10 ¹³ ohms-cm or about 1 × 10 ¹⁰ ohms-cm to about 1 × 10 ¹² ohms-cm It is made to provide resistance. In particular, at processing temperatures that rise from about 50 to 90 EC, which is required for high aspect ratio etching processes, this resistance value improves the performance of the dielectric 55 so that the power level applied to the second electrode 105 is maintained higher. do. Suitable dielectric 55 thickness is determined from about 0.02 mm to about 2.00 mm, and may be 0.05 mm to 1.00 mm.

Dielectric 55 includes aluminum oxide, aluminum nitride, boron nitride, boron carbide, carbon, cordierite, cerium oxide, diamond, mullite, silicon, silicon carbide, silicon nitride , Ceramic materials such as silicon oxide, titanium oxide, titanium boride, titanium carbide, iridium oxide, zirconium oxide, and mixtures and compounds thereof. For example, aluminum nitride provides high thermal conductivity, good heat transfer rate, and good corrosion resistance of about 80 to about 240 watts / mK. The resistance value of aluminum nitride can be controlled to a predetermined level by adding a trace amount of dopant material of about 0.5 to 5.0 wt%. In addition, the dielectric 55 may be formed by the second electrode (by freeze casting, injection molding, pressure-forming, thermal spraying, or sintering). 105 may be made of a monolith that surrounds it. For example, the ceramic material may be pressurized at elevated temperature to form a coherent mass having a porosity of less than 10%. For example, a suitable pressure forming device, including autoclave, platen press, and isostatic compression molding disclosed in US patent application Ser. No. 08 / 965,690, was filed on November 6, 1997, It is incorporated by reference in its entirety.

The plasma ion density and ion energy of the treatment region 112 may be further improved by the closely spaced first and second electrodes 115, 105. When the second electrode 105 is spaced at a relatively short distance from the first electrode 115, the resistance of the gas path therebetween is reduced, so that the electric field vector size between the two electrodes is relatively increased. As a result, the closely spaced electrodes 115, 105 more effectively couple energy to the gas in the chamber 100. In addition, the identified kinetic energy of the plasma ions can be increased due to the short separation distance between the electrodes 115, 105. In addition, the reduction in electrode spacing can make the flow of the processing gas across the substrate 10 more smooth and turbulent, thereby providing a more uniform treatment on the substrate surface. Thus, in one version, the first and second electrodes 115, 105 are spaced at a predetermined distance small enough to maintain a substantially laminar flow, with the spaced distance being less than about 5 cm and from about 1 cm to It can be 3 cm. To achieve the desired spacing, the second electrode 105 can be raised or the first electrode 115 can be lowered.

Increasing the intensity of the magnetic field in the chamber 100 can further enhance the etching of the high aspect ratio formation 29 in the substrate 10. Magnetic field strength is believed to affect the protective sidewall deposit 30 etched on the freshly etched formation 29 in the substrate 10. For example, in certain processes, as the magnetic field strength increases, the protective sidewall deposits 30 formed in the etching process become thicker, resulting in fewer recesses in the profile of the etched formation 29. Therefore, in particular, as the depth of the forming bodies 29 increases or their opening sizes become smaller, the magnetic field strength can be controlled so that the profile of the etched forming bodies 29 is optimized. For example, it has been found that upon etching of a formation 29 such as a trench, it is desirable to provide a high magnetic field having a magnetic field strength of at least about 100 Gauss or more or about 120 Gauss or more.

The magnetic field generator 292 may include an electromagnetic coil or a permanent magnet. For example, FIGS. 2 and 3 schematically illustrate one version of a magnetic field generator 292 that includes electromagnets 295, 300, 305, 310 proximate chamber 100. The magnetic field formed in the chamber 100 is a vector sum of the magnetic field generated by the electromagnets 295, 300, 305, 310 depending on the position relative to the treatment region 112 and the electrical energy provided to each electromagnet. The magnetic field generator 292 is a magnetic field substantially perpendicular to the plane of the substrate 10 that defines the plasma as the processing volume 112 on the substrate 10, a magnetic field parallel to the substrate surface, or plasma ions in the processing region 112. Can be configured to provide a magnetic field that is rotated to " stir. &Quot;

Also, as shown in FIG. 10, the magnetic field generator may include jackets 307 and 309 for circulating fluid therein. For example, the heat transfer fluid can be provided from the liner fluid source 121, the conductor fluid source 61, or other fluid source. This fluid is supplied to the fluid jackets 307, 309 for the electromagnets 305, 310, 295, 300 to control the magnet temperature. The heat transfer fluid can maintain the electromagnets 305, 310, 295, 300 at a constant temperature, and the circulation of such fluid can reduce the overheating of the electromagnet when a large current is applied through the electromagnet. This improves the electromagnet's ability to withstand large currents, thereby providing high magnetic field strength to the chamber 100. This increased magnetic field strength provides the substrate 10 with improved etching of the etched formation 29.

In one version, magnetic field generator 292 generates a multi-directional magnetic field with an angular orientation and magnitude that varies with time. This magnetic field may be generated by a plurality of electromagnets 295, 300, 305, 310 (or permanent rotating magnets) positioned in close proximity to the chamber 100. The electromagnet power source changes the current applied to the electromagnets 295, 300, 305, 310 and generates a multi-directional magnetic field in the plasma region. These magnetic fields are located in pairs with each other, generating a magnetic field that is substantially flat with the plane of the substrate 10. The power source ages a pair of electromagnets in a predetermined sequence to generate a magnetic field having an independently varying angular orientation and magnitude. As disclosed in US Pat. No. 5,255,024, which is incorporated by reference, the magnetic field generator 292 is not positioned adjacent to the sidewall 106 of the chamber 100, but instead includes a ceiling of the chamber, and / or a second electrode therein. It may be disposed under the dielectric 55 having a.

Alternatively, magnetic field generator 292 includes a plurality of movable permanent magnets located proximate to sidewall 106 of chamber 100. The magnet may be mounted on an armature (not shown) that rotates in a circular or elliptical orbit and / or linearly to generate a multi-directional magnetic field in the processing volume 112. Suitable permanent magnets include ferromagnetic materials such as nickel ferrite, cobalt ferrite, or barium ferrite.

The magnetic field generator 292 generates a magnetic field, which is a vector sum of the magnetic fields generated by each electromagnet or permanent magnet and depends on its position with respect to the chamber 100 and their mode of operation. In the version shown in FIG. 2, the magnetic field generator 292 is configured to generate a magnetic field having components that are substantially parallel to the surface of the substrate 10 and symmetric about an axis perpendicular to the substrate surface. In this version, the E × B drift velocity imparted to the electrons in the plasma moves and promotes the electrons in the plasma sheath at azimuth, in a circular path just above and on a plane parallel to the processing surface of the substrate 10. Magnetic field generator 292 provides magnetic vectors (By, Bx) that are generally parallel and mutually perpendicular to support and substrate 10, disclosed in US Pat. No. 5,215,619, which is incorporated by reference.

The magnetic field generator 292 transmits a control signal to the line 315, in order to control the magnitude and direction of the current to the electromagnets 295, 300, 305, 310 provided on the conductors 355, 360, 365, 370. It can be operated by a controller 160 that applies to the conventional power system 335, 340, 345, 350 via 320, 325, 330. The combined current determines the direction and magnitude of the field generated by each electromagnet. Alternatively, the controller 160 can be used to control the vibration of a set of permanent magnets of ferromagnetic material located in an amateur that can be rotated or linearly vibrated in a circular / elliptical shape. The vertical field vectors By and Bx generated by the magnetic field generator 292 are defined by the functions Bx = Bcos2 and By = Bsin2. Given the desired value of field, B, and angular orientation (2), controller 160 provides the desired field strength and orientation to combine to control the application of the required current with the electromagnet or to control the operation of the permanent magnet. The equation for obtaining the magnetic field vectors (By, Bx) is solved by itself to provide the desired magnetic field vectors (By, Bx).

That is, the angular orientation and magnitude of the magnetic field can change itself quickly or slowly by varying the rotational motion of the current or magnetic field in the electromagnets 295, 300 305, 310. The controller 160 can change the time the magnetic field is at each angular position, the direction of the angular stepping function, or the magnetic field strength. Thus, the magnetic field can be stepped around the substrate 10 using the selected orientation and time increment. If desired, the size result of the field B2 can be varied if the processing conditions or chamber structure require constant field strength. For example, the magnetic field can be rotated at a low speed of 2 to 5 sec / revolution to increase the 360 ° etching uniformity around the substrate 10.

In another embodiment, the magnetic field generator 292 is configured to provide a magnetic field having principal components approximately orthogonal to the plane of the substrate 10 (not shown). In another embodiment, the magnetic field generator 292 is configured to provide a magnetic field having an angled or curved component over the space or volume of the processing region 112 and on the plane of the substrate 10. (Not shown).

In another aspect of the present invention, the temperature control system 400 is provided to maintain a uniform temperature across the surface of the chamber 100, such as the substrate 10, or the surface to the inner wall 52 and the substrate support 124. ), A good etching of the high aspect ratio forming body is achieved. If the temperature from the substrate 10, components in the chamber 100, or from one substrate to another is non-uniform and inconsistent, the etch profile and etch rate for etching the high aspect ratio formation 29 It has been found that the temperature dependence is high and may vary significantly. The formed body 29 etched by this temperature change may have an inconsistent depth or other shape. In the etching process of the embodiment, a suitable substrate temperature is less than about 240 EC, and the change in temperature over the substrate hold is less than about 5 EC, for example, the substrate 10 is in a temperature range of about -40 to about 240 EC. Preferably, it can be maintained in the operating temperature range of about 200 to 240 EC.

In one version, the temperature control system 400 maintains a uniform heat transfer rate across the substrate 10 by providing a heat transfer gas such as helium at a water pressure below the substrate 10. For example, as shown in FIG. 10, the heat transfer gas is a plurality of heat transfer gas outlets 117i, 117o in different regions 99i, 99o on the receiving surface of the dielectric 55 from the heat transfer gas source 107. It may be provided as. The heat transfer gas promotes heat transfer between the substrate 10 and the dielectric 55. In one version, the spacing between the backside of the substrate 10 and the receiving surface 147 of the dielectric 55 is divided into two regions-one inner region 99i and one outer region 99o. Separate flow controllers 107o and 107i are used to provide independent control of the gas flow rate to each of the outer and inner regions. In addition, the individual gas flow controllers 107i and 107o allow the gas in each zone to be maintained at the same or different pressure. For example, the inner region may be maintained at 10-16 Torr, while the outer region may be maintained at 20 Torr. During processing, the substrate 10 can be non-uniformly heated by the plasma in the chamber 100, but by using two zone heat transfer gas control, the temperature across the substrate 10 can be made uniform. For example, the heat transfer gas pressures in the inner and outer regions can be controlled or kept nearly constant at a temperature difference from the center of the substrate 10 to the outer edge of less than about 5 EC.

In addition, during processing, the inner and outer heat transfer gas regions 99i 99o can be operated to induce thermal gradients formed over the substrate 10. For example, by adjusting the heat transfer gas pressures of the inner and outer regions 99i and 99o, the temperature at the center of the substrate 10 can be adjusted to be lower or higher than the temperature at the outer edge of the substrate 10. For example, if the center is etched faster than the outer edge in the substrate 10, or if the center is hotter than the outer edge, this version is preferred.

The temperature control system 400 further includes a conductor 62 disposed below the dielectric 55 and above the support base 200 to further control the rate of heat transfer between the substrate 10 and the support 124. You may. Conductor 62 is a conductive element capable of transferring thermal energy into and out of substrate 10 through dielectric 55 covering electrode 105 and in thermal contact with both substrate 10 and conductor 62. For example, as shown in FIG. 10, conductor 62 may include one or more channels 71 provided with a temperature controlled heat transfer fluid from conductive fluid source 61 via one or more fluid inlets 63. Can be. Heat transfer fluids, such as ethylene glycol and de-ionized water mixtures, are circulated through the channels in the conductors 62 to maintain the temperature of the conductors 62 at a constant level. For example, when the conductor 62 is heated to an undesirable high temperature during substrate processing, the heat transfer fluid provided to the channel 71 cools to lower the temperature of the conductor 62, thereby reducing the temperature from the substrate 10. Provides a uniform heat transfer rate. In addition, the heat transfer fluid is controlled by the controller 160 before being provided to the conductor 62 to maintain the substrate 10 at a desired temperature, for example about 80 to 100 EC during the trench etching of polysilicon. do.

Also, as shown in Fig. 2, the conductor 62 can be bonded or bonded to the dielectric 55 by an adhesive layer 73 made of a material having high thermal conductivity and uniformity. The adhesion of the conductor 62 and the dielectric 55 maximizes the rate of heat transfer from the dielectric 55 to the fluid in the channel 71 of the conductor 62. The adhesive layer 73 contains metals, such as aluminum, copper, iridium, or a tin-lead alloy. In addition, the adhesive layer 73 is a homogeneous component that provides a more uniform heat transfer rate across the substrate 10 and reduces the thermal impedance variation of the interface between the conductor 62 and the dielectric 55. In addition, the adhesive layer 73 provides a ductile interface that can absorb thermal stress caused by thermal expansion mismatch between the dielectric 55 and the conductor 62 without damaging the dielectric 55. do. Metal-bonded joints provide more uniform heat transfer rates, while these joints are difficult to withstand thermal stresses resulting from differences in the coefficients of thermal expansion of different materials. Therefore, the adhesive layer 73 can be made of a suitable material capable of absorbing thermal stress. Suitable adhesive materials include Thermattach T412 (TM) from Chomerics, Inc. Thermattach T412 is a high adhesive strength pressure sensitive acrylic resin adhesive applied to an aluminum carrier that is mixed with and expanded with titanium diboride. The thermal performance of the adhesive layer 73 can be improved by the combination of filter, expanded metal and embossed surface.

As shown in FIG. 4, the temperature control system 400 may further include one or more liners 104 covering at least a portion of the chamber wall 52. In one version, the chamber liner 104 may include a first (top) liner 134, a second (bottom) liner 118, or both the first liner 134 and the second liner 118. . The passage 119 located within each chamber liner 104 holds a heat transfer fluid, such as a liner fluid source 121 provided by a temperature controlled fluid supply system. In addition, the liner 104 may be of a single or removable structure such that cleaning or removal thereof is possible. Lower chamber wall 108 has holes 116 (only one in FIG. 4) to provide access to second liner 118 from outside of chamber 100. An O-ring 122 disposed in the groove 120 surrounds each hole 116.

In addition, the liner 104 is heated to reduce the deposition of the process residue on the liner 104 such that the process residue present in the chamber 100 affects the etch quality of the high aspect ratio formation in the substrate 10. You can adjust the amount. In one version, the heat transfer fluid from the liner fluid source 121 reduces the formation of treatment residues on the liner 104 by heating the liner through the liner 104. Reducing deposits of residue on chamber liner 104 may reduce the amount of treatment residue that flakes off liner 104 and back deposits onto substrate 10.

In addition, in the embodiment shown in FIGS. 1 and 4, the temperature control system 400 includes one or more heaters in proximity to the liners 118, 134, for example in proximity to the chamber ceiling 68. can do. Heater 67 may be used in conjunction with or alternatively to a heat transfer fluid passing through liners 118 and 134 that control ceiling 68 temperature. In one version, the heater 67 may include a coil or heating element, such as, for example, a heating coil 67 mounted on the lid assembly 102. The heater 67 is operated to heat the ceiling 68 or the liners 118, 134 during or before substrate 10 processing, such that temperature fluctuations in the chamber 100 are reduced. In particular, it has been found desirable to control the ceiling temperature by heating the ceiling 52 with a heater 67 and also circulating the fluid through the channel 59 in the ceiling 52. In this version, by using a dual heater and a fluid control method, the substrate 10 in the chamber 100 or in the middle of a processing step or in the case of treating the substrate 10 in the chamber 100 and heating the ceiling 52 with an energizing gas The temperature of the ceiling 52, which fluctuates when removing 10), will be adjusted more accurately.

The ceiling 52 and liner 104 have an opening including a first liner 134 and a lid 202 in the chamber ceiling 52, as in another version, for example one version shown in FIGS. 5 and 6. Possible lead assemblies 102 are included. The first liner 134 has a flange 342 located on the sidewall 106 and extending outward. The lid assembly 102 is clamped to the sidewall 106 by a pair of clamps 206. A first seal located between the sidewall 106 and the first liner 134 (eg, an O-ring seal 302 located in the groove 304 in the sidewall 106) may be formed of a first liner ( Provide a vacuum seal between 134 and sidewall 106. In addition, a second seal between the lid 202 and the first liner 134 (eg, an O-ring 306 located in the groove 304 within the lid 202) is between these components. Provide a tight gas seal. The lid assembly 102 is biased downwards normally when the leads 202 are properly clamped, and thus generates pressure on the second lid 118 downwards when installed in the processing chamber 100.

The first liner 134 is formed of a thermally conductive material such as anodized aluminum, stainless steel, ceramic or other suitable material. The first liner 134 includes a central portion 341 having a dish-shaped upper surface 312 and a lower surface 316. The dish-shaped upper surface 312 has a protrusion 314 connected with the flange 342 extending outwardly. Cylindrical wall 318 extends from lower surface 316. Lower surface 316 and wall 318 have exposed surface 343 exposed to treatment volume 112.

In another aspect of the present invention, deposition of the treatment residue on the first liner 134 is reduced by providing an exposed surface 343 having a relatively smooth surface having a peak to peak RMS surface roughness of less than about 32. do. A relatively smooth surface because it reduces the amount of processing material deposited on the liner 134, thereby improving the etching of the high aspect ratio formation of the substrate 10 by reducing the formation of excess processing residue on the liner 134. It was found that this is desirable. Excess accumulation of process residues around the substrate 10 results in high concentrations of process residue forming species around the substrate 10 and causes deposition of excess process residues on the etched formations of the substrate 10. It has been known to. Excess residue results in poor etching of high aspect ratio properties.

5 and 6 show one version of the fluid passageway in the first liner 134. In this version, the recess 314 of the central portion 341 can be formed by casting or drilling a plurality of intersecting holes, each of which is closed by a plug 210. Fluid passageway 322. Each end of the fluid passage 322 is connected to the upper surface 312 by a bore 324. Two bosses 326 (only one is shown in FIG. 6) protrude from the upper surface 312 of the central portion 341. Each boss 326 has a center hole 328 that is connected to allow fluid to pass through the respective bore 324 into the fluid passage 322. The fluid passage 322 receives fluid from the liner fluid source 121, and the temperature of the first liner 134 is adjusted by transferring the heat to the first liner 134. By circulating fluid from the liner fluid source 121 through the first liner 134, the amount of heat provided to the first liner 134 is controlled to maintain the first liner at a predetermined temperature. Fluid, such as liquid and / or gas fluid, flows through the fluid passage 322 to control the temperature of the first liner 134. The fluid may be a liquid such as deionized water and / or ethylene glycol or a fluid such as liquid or solid nitrogen or Freon (Freon, TM Dupont de Nemours, Ailmington, Delaware).

Those skilled in the art can create other configurations than the embodiments provided herein. For example, as shown in FIG. 7, the lid assembly 202 can include a first fluid passage 322a and a second fluid passage 322b. As shown in FIG. 7, the first and second lead passages 322a, 322b may share a common inlet 330i and a common outlet 330o. Alternatively, additional inlets and outlets may be used. The first and second fluid passages 322A, 322B can also be double backed in a two tube passage configuration. Additional tube passages may also be included in other ways.

5 and 6, the liner fluid supply 121 is used with a quick connect fluid coupling to facilitate quick removal and replacement of the first liner 134 from the chamber 100. ) And the first liner 134 may be connected to allow fluid to pass through. Typically, the quick connect 336 of the male pipe thread-form is inserted into the female thread-form of the center hole 328 of the boss 326. The paired coupling 332 is secured to the terminal end of the fluid supply line 334. The fluid supply line 334 connects the passage 322 to the liner fluid supply 121. One advantage of this configuration is that the fluid supply line 334 can be easily separated when the first liner 134 is replaced. However, as another method of coupling the first liner 134 to the fluid supply line 334, for example, pipe threads, barbed nipples, collect connectors, and the like can be used. Quick connects are commercially available and are usually chosen based on port size (thread-shape and flow capacity).

The liner wall 318 is sized to slide inside the sidewall 106 with minimal spacing. The liner wall 318 may vary in height and extend to the chamber bottom 108 when used without the second liner. Typically, when both the first liner 134 and the second liner 118 are used as shown in FIG. 4, the liner is lower in the chamber 108 around the hole 116 when the lid assembly 102 is clamped. In order to provide the necessary compressive force for the O-ring 122 sealing the second liner 118, it has a shape and size suitable for the interior of the chamber 100. The liner wall 318 may further include a plurality of other ports for various purposes. One example of such another port is a substrate access port that is aligned along the slit opening of the chamber 100.

Referring again to FIG. 4, at least a portion of the second liner 118 surrounds the bottom of the chamber volume 110. In addition, the second liner may be configured to provide a relatively hot and smooth surface with 32 peak-to-peak RMS roughness within the chamber volume 110 to reduce deposits of processing material on the liner 118. Second liner 118 has a fluid passageway 119 through which fluid is provided from liner fluid source 121 by conduit 123. The fluid regulates the temperature of the second liner 118 by transferring heat from the fluid to the second liner 118. As the fluid is circulated from the liner fluid source 121 through the second liner 118, the amount of heat provided to the second liner 118 is controlled, thereby allowing the second liner 118 to be maintained at a predetermined temperature. .

8 and 9 show one version of a second liner 118 that includes a base 502 and an outer wall 506. The inner surface 508 and outer wall 506 of the base 502 are exposed to the pumping volume 114. The second liner 118 may be made of a thermally conductive material, such as anodized aluminum, stainless steel, or other compatible material. The base 502 includes a fluid passage 119 that can be formed, for example, by casting, or by plugging an opening and then milling a groove. Alternatively, the fluid passage 119 can be formed by drilling through blind holes and plugging the opening ends of the holes, as shown in FIG. 8. In one embodiment, the fluid passage 119 is close to a circle that starts and ends close to the outlet port 520 disposed through the second liner 118. Each end of the fluid passage 119 terminates in a boss 510 protruding from the outer surface of the base 502. The boss 510 contacts the hole 116 in the bottom wall 108 and ensures proper orientation of the second liner 118 in the chamber 100 (eg, port alignment). To facilitate rapid exchange of the second liner 118, a quick connect fluid coupling between the conduit 123 and the second liner 118 that couples the passage 119 to the liner fluid source 121 for fluid to pass through. This is used. Typically, a SAE port is used that is coupled with an O-ring or a quick connect 512 having a male pipe thread shape inserted into the female thread-shape within the boss 510. A paired coupling 514 is attached to the terminal end of the conduit 123 that is coupled to the fluid supply 121. That is, when the second liner 118 is changed or replaced, the conduit 123 can be easily separated. However, other means of coupling the second liner 118 to the liner fluid supply 121 may be used differently.

Typically, the outer wall 506 is cylindrical and sized with a minimum distance from the chamber wall. As mentioned above, the outer wall 506 may vary in height when the first liner 134 is used. The outer wall 506 further includes an outlet port 520 that is aligned with the pumping port 138. The discharge port 520 may partially surround a portion of the base wall 108. Discharge port 520 provides fluid access to throttle valve 60 and pump 109 of the gas in pumping volume 114. The outer wall 506 may further include a plurality of different ports for various purposes. An example of such another port is a substrate access port 526 that is aligned with the slit opening 139 of the sidewall 106 to transfer the substrate 10 into and out of the chamber 100.

An advantage of the liner configuration described above is that the use of a pair of liners 134, 118 can minimize chamber down time for liner cleaning. If liner replacement is needed, the clamp 206 is opened and the lid assembly 102 is released. Each liner is separated from the fluid source 121 by separating the quick connects. The lid 202 and gas feedthrough 212 are separated from the first liner 134, and the first liner 134 is lifted out of the chamber 100. Once the first liner 134 is removed, the second liner 118 is similarly removed. Chamber down time is minimized by replacing liners 134 and 118. The lid 202 and gas feedthrough 212 are located on the replacement first liner 134. The clamp 206 is closed, ie the seal is compressed, and the chamber volume 110 is sealed. Each replacement liner reconnects the fluid source 121 to complete the liner change procedure. The removed liner may be cleaned to remove accumulated byproducts and then ready for re-installation into chamber 100 where liner replacement is desired.

Also, in another aspect of the temperature control system 400, the base 200 of the support 124 can include one or more heat transfer fluid conduits 201 to control the temperature of the chamber. For example, conduit 201 may be disposed to transfer heat between the surfaces of the peripheral support 124 of the base 200 and to transfer heat transfer fluid within the conduit 201. In addition to controlling the temperature of the processing chamber, the temperature controlled base 201 can ensure that the temperature of the surface relative to the support 124 is maintained at a high temperature sufficient to prevent the deposition of processing residues onto the surface.

The operation of the temperature controlled liner 104 and the support base 200 according to the present invention is shown in FIG. 10. In operation, the temperature of the first liner 134 and the second liner 118 is controlled by flowing fluid from the liner fluid source 121 through the passages 119, 322 in the respective liners 118, 134. Upon exiting the passages 119, 322, the heat transfer fluid may be combined into a single conduit before flowing to the heat transfer fluid conduit 201 in the support base 200 and back to the liner fluid source 121. The heat transfer fluid is provided to regulate the temperature of the liner 118, 134 and the base 200 by transferring heat between the liners 118, 134 and between the base 200 and the fluid. The temperature and flow rate of the fluid from the liner fluid source 121 can be controlled to regulate the heat transferred to the liner 118, 134 and the base 200 by the heat transfer fluid. In one version, the user releases the fluid discharged from the liner fluid source 121 to maintain one set point, for example, a user input set-point for the temperature of the liner walls 118, 134 and the base 200. May be provided to the controller 160, which has adjusted the amount and temperature. Suitable liner temperatures that can reduce the deposition of treatment residues on liner 104 can be from about 50 to about 70 EC.

Components of a temperature control system comprising a dielectric 55 having a plurality of region backside heat transfer gases, a support base 200 comprising a heat transfer fluid conduit 201, a conductor 62 and an adhesive layer 73, The fluid circulation liner 104 and the heater 67 can control the temperature of the substrate 10 by, for example, removing heat generated during the plasma process of the substrate 10. The heat transfer efficiency provided by the temperature control system 400 ensures that high RF power levels and magnetic fields applied to the chamber, even RF power levels above 3200 watts and magnetic fields greater than 100 Gauss, are maintained for long periods of time, Can be used.

That is, aspects of the chamber 100 serve to provide high etch rate etching of the formation on the substrate 10 to provide a good etch rate. For example, gas energizer 141 provides a sufficiently high power density that allows formation 29 to be highly energetically etched. The magnetic field generator 292 maintains a good formation profile by providing the chamber 100 with a sufficiently high magnetic field strength. The temperature control system 400 provides an appropriate temperature to the chamber by, for example, controlling the temperature of the substrate 10 to etch the high aspect ratio formation on the substrate 10 at a good etching rate. In addition, the temperature control system 400 reduces the amount of treatment residue deposited on the chamber 100 surface, thereby improving the etching of the high aspect ratio formation at a good etch rate. For example, temperature control system 400 can heat liner 104 to reduce the deposition of treatment residues on liner 104 surface. In addition, the liner 104 may comprise a relatively smooth surface so as not to promote adhesion of the treatment residue to the liner 104 surface. In addition, the ejector 114 removes the treatment residue from the chamber 100 at a rate high enough to reduce the deposition of the treatment residue on the surface of the chamber 100, thereby providing a good etching of the high aspect ratio forming body 29. Help etch at speed Deposition of process residues to the chamber surface reduces the amount of process residues that are peeled off the surface and deposited back to the substrate 10, thereby providing a high aspect ratio etch at a good etch rate. The components of the chamber 100 serve to provide a suitable chamber atmosphere in which etching of high aspect ratio formations of good etch rate can be made in the substrate.

The chamber 100 is a CPU such as a 68040 microprocessor manufactured by Synergy Microsystems of California or a Pentium processor manufactured by Intel Corporation of Santa Clara, California, connected to the memory 193 and peripheral computer components, as shown in FIG. may be operated by a controller 160 that includes a central processor unit 174. The memory 193 includes a computer readable medium having the computer readable program 189 implemented therein. Preferably, memory 193 may include hard drive 187, CD or floppy drive 188, and RAM 172. The controller 100 may further include a plurality of interface cards including analog and digital input / output boards, interface boards, motor controller boards, and the like. For example, the interface between the user and the controller 160 can be through the display 190 and the light pen 194. The light pen 194 detects light emitted from the monitor display 190 with an optical sensor in its tip. To select a particular screen and function, the user touches the designed area of the screen on the monitor 190 and pushes a button on the light pen 194. In general, the touched area is changed in color, or a new menu is displayed to confirm communication between the user and the controller 160.

Computer-readable program 189 may be stored in memory 193 or may be a computer program product stored on CD or floppy disk drive 188 or other suitable drive. Typically, the computer readable program 189 is, for example, program code for operating the chamber 100 and its components, as shown in FIG. 11, and process monitoring to monitor the processing performed in the chamber 100. Processing control software 533 including software, safety system software, and other control software. Computer-readable program 189 may be written in a conventional computer-readable programming language, such as Assembly language, C ++, Pascal, or Forran. Appropriate program code is entered into a single file or a plurality of files, using conventional text editors and stored or implemented as computer-available files in memory 193. If the input code text is a high level language, the code is compiled and the compiler code result is linked to the object code of the precompiled library routine. To execute the compiled and linked object code, the user invokes the object code, causing the CPU 174 to read and execute the code, to perform the task identified in the program.

11 is an exemplary block diagram of a hierarchical control structure in accordance with certain embodiments of computer readable program 189 in accordance with the present invention. Using the light pen interface, the user enters the process settings and chamber number into the process selection program 530 in response to a menu or program displayed on the CRT terminal. Process chamber program 533 includes program code for setting the time, gas composition, gas flow rate, chamber pressure, chamber temperature, RF power level, support position, heater temperature, magnetic field generation, other parameters, and the like for a given process. . The process setting is a predetermined group of process parameters required to perform a predetermined process. Processing parameters are unrestricted processing conditions including gas composition, gas flow rate, temperature, pressure, gas energizer settings such as RF or microwave power level, magnetic field generation, heat transfer gas pressure, and wall temperature.

The process sequence program 531 includes program code for receiving the setting of the chamber type and the process parameters from the process selection program 530 and controlling the operation. The sequence program 531 is a chamber management program 532 that controls a plurality of processing jobs in the processing chamber 100, and starts execution of a set process by passing predetermined process parameters. Generally, the processing chamber program 533 includes a substrate positioning program 534, a gas flow control program 535, a gas pressure control program 536, a gas energizer control program 535, a temperature control system control program 453. ), And magnetic field generation program 544. Typically, the substrate positioning program 534 loads the substrate onto the support 124 and additionally program code for controlling the chamber components used to lift the substrate 10 to a predetermined height in the chamber 100. It includes. The process gas control program 535 includes program code for controlling the flow rates of different components of the process gas. The process gas control program 535 controls the opening and closing positions of the safety shut-off valves to obtain the desired gas flow rate, and ramps the gas flow controllers 107o and 107i on and down. down) The pressure control program 536 includes program code for controlling the pressure in the chamber 100 by adjusting the opening size of the throttle valve 60 of the discharge system 110 of the chamber 100. The gas energizer control program 537 includes program code for setting the RF power level applied to the process electrodes 115 and 105 in the chamber 100. The temperature control system controller includes program code for controlling the temperature in the chamber 106. For example, the temperature control system controller can set the temperature or flow rate of the heat transfer fluid and heat transfer gas to obtain a desired predetermined temperature of chamber components, such as chamber liner 104 or support 124. The magnetic field generation program 544 includes program code for controlling the magnetic field generator 292, such as setting the strength of the magnetic field applied to the chamber 100.

Data signals received and / or evaluated by the controller 160 may be delivered to a factory automation host computer 191. The factory automated host computer 191 evaluates data from a plurality of systems, platforms, or chambers 100, and (i) the substrate 10 for placement of the substrate 10 or over an extended period of time. Identification of statistical processing control parameters of processing performed on a substrate, (ii) properties that can change in a statistical relationship across a single substrate 10, or (iii) properties that can change the placement of a substrate 100 in a statistical relationship Host software program 192. In addition, the host software program 192 may use data to proceed in the in-situ process evaluation or to control other process parameters. Suitable host software programs include the WORKSTREAM ^™ software program, a product of Applied Materials described above. The factory autohost computer 191 may (i) remove a particular substrate 10 from a processing sequence if substrate characteristics are unsuitable or deviate within a predetermined range, or if processing parameters deviate from an acceptable range, (ii) ) May be further configured to provide a command signal for final processing in a particular chamber 100, or (iii) controlling processing conditions in the determination of inappropriate characteristics or processing parameters of the substrate 10. In addition, the factory automated host computer 191 may provide a command signal at the beginning or the end of processing the substrate 10 in response to the evaluation of the data by the host software program 192.

Yes

The following example clarifies the effect of the present invention; The present invention can be used for other processing and other uses that are apparent to those skilled in the art, and are not limited to the examples provided herein. In this example, a single-wafer processing chamber, according to the present invention, was used to etch a substrate 10 comprising silicon dioxide on a silicon wafer having a diameter of about 200 mm.

Substrate 10 was positioned on substrate support 124, which was heated or cooled by passing a heat transfer fluid through a channel of conductor 62 therein. The substrate 10 was equilibrated to the temperature of the chamber 100, and the pressure in the chamber 100 was set by adjusting the opening size of the throttle valve 60 of the ejector 110. In the etching process, for about 25 L of chamber volume, a processing gas was injected into the chamber 100 comprising 100 sccm of HBr, 18 sccm of NF ₃ and 36 sccm of HeO ₂ . Thereafter, an RF voltage was applied to the electrode 105 at an RF power level. The magnetic field generator 292 applied a magnetic field to the chamber 100. The substrate 10 was cooled by the heat transfer gas controllers 107i and 107o by the helium heat transfer gas 107 at different pressures applied to the substrate receiving surface 147.

Examples 1 to 3

These examples have been carried out to determine the effect of the RF power level on the temperature of the electrode 105 during the etching of the substrate 10. The support 124 was heated to a temperature of 90 EC and the pressure in the chamber 100 was maintained at 230 mTorr. Thereafter, the etching gas composition was provided to the chamber 100, the RF power level was set to 1800, 2600, or 3490 watts, and a 100 Gauss magnetic field was applied. The heat transfer gas controllers 107i and 107o supplied helium gas at 16 and 20 mTorr pressures to the back side of the substrate 10. Substrate 10 was etched for 240 minutes.

12 shows the temperature change of the electrode 105 with increasing RF power applied to the electrode 105. The increase in electrode temperature was measured to be 6.8 EC at an RF power level of 1800 watts, 8.5 EC at 2600 watts, and 13.6 EC at 3490 watts. The electrode temperature, ie the substrate temperature, was determined to rise as a function of RF power level. The equation describing this function was determined to be a polynomial function of the RF power level applied to the electrodes 105, 118. These examples show that the substrate temperature is highly dependent on the RF power applied to the electrodes 105, 118 and affects the etch rate and profile of the formed body 29 that was etched from the substrate 10.

Examples 4-6

13A-13C show the effect of the RF power level on the profile of the etched formation 29 and the rate at which the formation 29 is etched. The etching process was performed on the substrate 10 at a chamber pressure of 170 mTorr, magnetic field strength of 100 Gauss, electrode temperature of 90 EC, and RF power levels of 1250, 1450, 1600 watts as described above. 13A shows the trench width and critical area obtained when increasing the RF power level. Typically, increasing the RF power level has increased the average profile width and the average critical area of the top of the etched formation. An average width of 0.16 Φ m and an aperture size critical area of 0.18 Φ m were obtained at RF power of 1250 watts, while an average width and an aperture size critical area of 0.23 were obtained at 1600 watts RF power. 13B shows the etch rate and aspect ratio obtained as the RF power level increases. As the RF power level increased, the etch rate increased and the aspect ratio decreased. The average etch rate increased from 0.72 Φ m / min at 1250 watts to 0.82 Φ m / min at 1600 watts. The average aspect ratio for an RF power level of 1250 watts was 36.4, while the average aspect ratio for an RF power level of 1600 watts was 33.2. 13C shows the etch rate and selectivity obtained with increasing RF power level. Average selectivity increased from 9.8 at 1250 watts to 11.2 at 1600 watts. Typically, these results indicate that increasing RF power increases the average etch rate and maintains good etch selectivity. However, increasing the RF power level also results in an undesirably increased trench width and reduced aspect ratio, believed to be due to the dependence of the RF power level on the wafer temperature. Therefore, it is desirable to use an RF power level increase in the etching process to increase the etching rate. However, to obtain the high aspect ratio former 29, other processing parameters must be optimized at the selected RF power level.

Examples 7 to 8

In these examples, magnetic field strength has also been found to be a parameter that can be optimized to maintain a narrow etched formation width upon increasing RF power level. 14A-14C show the effect of increasing the magnetic field strength during the etching process. Etching treatments were performed at chamber pressures of 130, 135, or 140 mTorr, RF power levels of 1250 watts, cathode temperatures of 90 EC, and magnetic field strengths of 80 or 100 Gauss. 14A shows the trench widths and critical dimensions obtained when increasing the magnetic field strength. The average width of the etched formations 29 was found to decrease from 0.18 phi m at 80 Gauss to 0.16 phi m at 100 Gauss. The critical dimension of the etched formation 29 was found to decrease from an average critical dimension of 0.18 Φ m at 80 Gauss to an average critical dimension of 0.16 Φ m at 100 Gauss. 14B shows the etch rate and aspect ratio obtained with increasing magnetic field strength. The average former etch rate was found to increase from 0.67 Φ m / min at 80 Gauss to 0.73 Φ m / min at 100 Gauss. The increase in average etch rate was accompanied by a reduction in the aspect ratio of the etched formation. The average aspect ratio of 80 Gauss was measured at 33.0, while the average aspect ratio of 100 Gauss was measured at 32.7. 14C shows the etch rate and selectivity obtained with increasing magnetic field strength. Average selectivity appears to increase from 10.4 at 80 Gauss to 11.2 at 100 Gauss. That is, using high magnetic field strength can increase the etch rate while at the same time maintaining a good etch profile, high aspect ratio and narrow trench width. Therefore, it is desirable to carry out the high aspect ratio forming body etching process at high magnetic field strength.

Examples 9-10

The effect of increasing the magnetic field strength of the etch process was further tested by comparing it with the etch process performed at 100 and 120 Gauss magnetic field strengths and RF power levels of 1450 watts. Chamber pressure was maintained at 170 mTorr and electrode temperature was set to 90 EC. The average etching rate for processing performed at a magnetic field strength of 120 Gauss was found to be 0.78 Φ m / min with an aspect ratio of 34.0. This value is substantially more desirable than the average etch ratio of 0.756 and the average aspect ratio of 33.5 obtained at a magnetic field strength of 100 Gauss. Higher magnetic field intensities are believed to maintain the high aspect ratio and further narrow the trench width by controlling the deposition of the protective sidewall splice 30 during the etching process. This example also shows that the high magnetic field strength improves the etching of high aspect ratio formers.

Examples 11-18

In this comparative example, the etching process using higher RF power and the etching process using lower RF power were compared. The etch rates obtained in the etching process together with the shape of the etched formations are shown in Table 1 below.

In Examples 11-13, the etching process was performed at an RF power level of 900 watts, at the same time, the electrode was maintained at a temperature of 90 EC, the chamber pressure was maintained at 200 mTorr, and the helium pressure was measured in a single heat transfer gas region (99 ) Was maintained at 14 Torr on the support 124 and the magnetic field was maintained at a high level of 100 Gauss.

In Examples 14-16, the etching process was performed at an RF power level of 1800 watts, while the electrode was maintained at a temperature of 90 EC, the chamber pressure was maintained at 230 mTorr, and the helium internal and external outlet pressures were 14 and It was maintained at 20 Torr and the magnetic field was maintained at a high level of 100 Gauss.

In Example 17, the etching process was performed at an RF power level of 1800 watts, while the electrode was maintained at a temperature of 90 EC, the chamber pressure was maintained at 200-230 mTorr, and the helium internal and external outlet pressures were 6- It was maintained at 14 Torr and 15-20 Torr, and the magnetic field was maintained at a high level of 100 Gauss.

In Example 18, the etching process was performed at an RF power level of 2600 watts, while the electrode was maintained at a temperature of 70 EC, the chamber pressure was maintained at 230 mTorr, and the helium internal and external outlet pressures were 10-16 Torr and It was maintained at 20 Torr and the magnetic field was maintained at a high level of 100 Gauss.

These examples show that an etch process using a high RF power level obtains an etched formation having a high aspect ratio at a faster average etch rate than an etch process using a lower RF power level.

Possible example

The following is a possible example to simulate the exemplary process of the present invention having a good etch rate profile and providing a high etch rate. In this example, the etching process is performed at an electrode temperature of 50 to 60 EC, internal and external gas region helium pressures of 16 Torr and 20 Torr, RF power level of 3500 watts, and magnetic field strength of 100 Gauss, respectively. Process gas composition and gas pressure are the same as provided herein. Using these optimized parameters, it is expected that a good etch profile can be achieved at an etch rate of about 1.3 Φ m / min or more. This represents a substantial increase over the baseline etch process performed at RF power levels of 1800 watts and magnetic field strengths of 100 Gauss. That is, it is expected that high etch rates and good etch profiles will be obtained by increasing the RF power level.

The apparatus 50 and the process of the present invention provide a good etching of the high aspect ratio forming body 29 on the substrate 10, which has a good etching profile and a consistent etching rate. The apparatus 50 can provide high RF power levels while at the same time providing a high intensity magnetic field and good temperature control. Substrate 10 processing, which maintains the substrate at a predetermined temperature and at the same time provides high RF power levels and strong magnetic field strengths, allows for etching of high aspect ratio formation at good etch rates. Unexpectedly, it has been found that high RF power levels provide good etch rates for high aspect ratio formations and high magnetic field strengths maintain small critical dimensions and aperture size of high aspect ratio formations. In addition, maintaining the substrate at a predetermined range of temperatures improves the shape of the etched formed profile. In addition, the deposition of process residues into chamber 100 substrates has been found to allow etching of high aspect ratio formation at good etch rates. As a result, the etching apparatus and the process according to the present invention can etch the high aspect ratio formation at a high etching rate and maintain a small opening size and a good profile of the etched formation.

Although illustrative embodiments of the present invention have been illustrated and described, other embodiments may be devised within the scope of the present invention. For example, additional electrodes can be used that operate at different power levels without departing from the scope of the present invention. In addition, as will be apparent to one skilled in the art, the magnetic field generator may include other magnetic field sources. Further, the following, above, below, above, above, below, first and second, and other relative terms or position terms are shown to correspond to the exemplary embodiments of the drawings and are mutually compatible. Accordingly, the appended claims are not limited to the description of the preferred versions, materials, and spatial arrangements that have been described herein.

Claims (32)

A gas supply for providing gas to the chamber; First and second electrodes that can be electrically biased to energize the gas, the second electrodes being configured to be charged at a power density of at least about 10 watts / cm 2 and including a receiving surface for receiving a substrate; First and second electrodes; And And an ejector for exhausting the gas. The substrate processing chamber of claim 1, wherein the second electrode is configured to be capable of being charged at about 3200 watts or more for a substrate having a diameter of about 200 mm. The substrate processing chamber of claim 1, comprising a magnetic field generator configured to provide a magnetic field of at least about 100 Gauss to the chamber. 4. The substrate processing chamber of claim 3, wherein the magnetic field generator comprises an electromagnet having a jacket therein for circulating a heat transfer fluid therein. The apparatus of claim 1, comprising a controller configured to control the first and second electrodes, the magnetic field generator, and a temperature control system to set processing conditions for etching a substrate formation having an aspect ratio of about 30 or more. A substrate processing chamber, characterized in that. 6. The substrate processing chamber of claim 5, comprising a controller configured to set processing conditions for etching a substrate formation having an opening size of about 0.14 mm or less or a depth of about 8 mm or more. The substrate processing chamber of claim 1, comprising a temperature control system configured to control the temperature in the chamber. 8. The substrate processing chamber of claim 7, comprising a temperature control system to allow the substrate to be maintained at a temperature below about 240 EC or at a temperature varying below about 5 EC. The method of claim 7, wherein the temperature control system, (a) a substrate receiving surface having a plurality of regions in which heat transfer gas can be maintained at different pressures during processing of the substrate; (b) a conductor positioned below said second electrode and including a channel for circulating a heat transfer fluid therein; (c) a liner comprising a smooth surface; And (d) a chamber wall having a heater configured to heat the passage or chamber wall for circulating a heat transfer fluid therein, And at least one of the substrate processing chambers. 10. The substrate processing chamber of claim 9, wherein said temperature control system comprises a conduit for circulating a heat transfer fluid at the bottom of said conductor. The substrate processing chamber of claim 1, wherein the first and second electrodes are spaced at a distance of about 1 cm to about 5 cm. 12. The substrate processing chamber of claim 11, wherein the gas supply includes a gas outlet at one of the electrodes. The substrate processing chamber of claim 1, wherein the second electrode comprises a dielectric covering a conductor, the dielectric having a resistivity of about 1 × 10 ⁹ to 1 × 10 ¹³ ohms-cm. The substrate processing chamber of claim 13, wherein the dielectric has a resistivity of about 1 × 10 ¹⁰ to 1 × 10 ¹² ohms-cm. The substrate processing chamber of claim 13, wherein the dielectric has a thickness of about 0.02 to about 2 mm. (a) providing a substrate in a processing region; (b) injecting gas into the processing region; (c) energizing the gas by applying electrical energy to an electrode below the substrate at a power density of at least about 10 watts / cm ² ; And (d) discharging said gas. 17. The method of claim 16, comprising applying a magnetic field of at least about 100 Gauss to the processing region. 17. The method of claim 16, comprising maintaining the substrate at a temperature below about 240 EC or at a temperature varying below about 5 EC. 18. The method of claim 16, wherein processing conditions are set to include energizing the gas, maintaining a magnetic field, and controlling the substrate temperature to etch a substrate former having an aspect ratio of about 30 or greater and an aperture size of less than about 0.14 Φm. Substrate processing method comprising the step of. Substrate support; A gas provider for providing gas to the chamber and an discharger for discharging the gas in the chamber; A first and second electrode that can be electrically biased to energize the gas, the second electrode configured to be capable of being charged with power of at least about 3200 watts to a substrate having a diameter of about 200 mm Energizer; A magnetic field generator configured to provide a magnetic field of at least about 100 Gauss to the chamber; And A temperature control system configured to control the temperature of the substrate and the chamber surface. 21. The substrate etching chamber of claim 20, wherein the magnetic field generator is configured to provide a magnetic field of at least about 120 Gauss to the chamber. 21. The substrate etch chamber of claim 20, wherein the temperature control system is configured to maintain the substrate at a temperature that is less than about 240 EC or less than about 5 EC. 21. The system of claim 20, wherein the first and second electrodes, the magnetic field generator, and the temperature control system are configured to set processing conditions for etching a substrate formation having an aspect ratio of at least about 30 and an aperture size of less than about 0.14 [phi] m. And a controller to control one or more of the substrate processing chambers. 21. The substrate processing chamber of claim 20, wherein said temperature control system comprises a liner having a smooth surface. 21. The substrate processing chamber of claim 20, wherein said second electrode comprises a dielectric covering said conductor, said dielectric having a resistivity of about 1x10 ⁹ to about 1x10 ¹³ ohms-cm. (a) providing a substrate in a processing region of the chamber; (b) injecting gas into the processing region; (c) energizing the gas by combining the gas with electrical energy of about 3200 watts or more for the substrate having a diameter of about 200 mm; (d) applying a magnetic field of at least about 100 Gauss to the chamber; (e) controlling the temperature of the substrate and the chamber; And (f) evacuating the gas. 28. The method of claim 27, comprising applying a magnetic field of at least about 120 Gauss to the chamber. 28. The method of claim 27, wherein the gas is energized by charging an electrode coated with a dielectric having a resistivity of about 1x10 ⁹ to about 1x10 ¹³ ohms-cm. 28. The method of claim 27, comprising maintaining the substrate at a temperature below about 240 EC or at a temperature varying below about 5 EC. A etched formation having an aspect ratio of at least about 30 and an aperture size of less than about 0.14 Φm. 31. The substrate of claim 30, wherein the etched formation has an aspect ratio of at least about 45. 31. The substrate of claim 30, wherein the etched formation has an opening size of less than about 0.10 [phi] m.